To automatically apply a brake when a specific rotary shaft exceeds the prescribed revolving speed at the time of the runaway of a machine body by providing an abnormal rotation braking mechanism operated and coupled with a brake device via an increase in centrifugal force based on the fixed revolving speed or above of an output shaft between the output shaft and the brake device.
An abnormal rotation braking mechanism 32 is constituted of a pendulum 38 rotated around a pin 37 erected on the side face of an output sprocket 36 fixed to the output shaft 34 of a transmission 22, a shifter 40 restrained with the movement on the output shaft 34 by the pendulum 38, and a brake device 42 fitted to a fixed wall and couplable with the shifter 40. When the output shaft 34 becomes the fixed revolving speed or above at the time of the runaway of a machine body, the pendulum 38 is opened against a spring 44 based on an increase of centrifugal force, and it is separated from the large- diameter section 48 of the shifter 40. The shifter 40 is moved near to a brake wheel 50 side by the force of a spring 46, their coupling pawls 56 are coupled with each other, and braking force is applied to the output shaft 34.
ISHINO TADASHI
TAKADA KAZUMI
OYAMADA YASUYUKI
